1670-80;French: name for a number of seesawlike mechanical devices, Middle Frenchbacule, noun derivative of baculer to strike on the buttocks (probably orig., to land on one's buttocks), equivalent to bas down (see base2) + -culer, verbal derivative of cul rump, buttocks (see culet); -s- by false analysis as bas(se) adj. + cule taken as a feminine noun